749 research outputs found
Chondromyxoid fibroma management: a single institution experience of 22 cases
Background: Several different strategies have been reported for the treatment of chondromyxoid fibromas, all with variable outcomes and high recurrence rates. Methods: We report on 22 consecutive cases of chondromyxoid fibromas treated by intralesional curettage, four of which had adjuvant cementation at our institution between 2003 and 2010. We assessed the functional outcome using the Musculoskeletal Tumour Society (MSTS) scoring system. Results: Nine males and 16 females with a mean age of 36.5 years (range 11 to 73) and a mean follow-up of 60.7 months were included in the study. Local recurrence occurred in two patients (9%) within the first 2 years following the index procedure. This was treated by re-curettage only of the residual defect. Two postoperative complications occurred: a superficial wound infection in one patient and a transient deep peroneal nerve neurapraxia in the other. The mean postoperative MSTS score was 96.7%. Conclusions: Intralesional curettage and cementation is as an effective treatment strategy for chondromyxoid fibromas, providing satisfactory functional results with a low recurrence rate. Careful case selection with stringent clinical and radiographic follow-up is recommended
Acoustic Emission During Intergranular Stress Corrosion Cracking
The physical and chemical processes taking place during intergranular stress corrosion cracking (IGSCC), in particular the effects of impurities on cracking mechanisms, have been the subjects of a research program sponsored by the Division of Materials Science, Office of Basic Energy Science, U. S. Department of Energy at Pacific Northwest Laboratory (PNL), operated by Battelle Memorial Institute. Acoustic emission (AE) was brought into the program because of the unique ability of AE methods to detect dynamic microscopic fracture processes. In this paper, the results of these tests are presented.</p
The challenges of implementing packaged hospital electronic prescribing and medicine administration systems in UK hospitals: premature purchase of immature solutions?
The UK National Health Service is making major efforts to implement Hospital Electronic Prescribing and Medicine Administration (HEPMA) to improve patient safety and quality of care. Substantial public investments have attracted a wide range of UK and overseas suppliers offering Commercial-Off –The-Shelf (COTS) solutions. A lack of (UK) implementation experience and weak supplier-user relationships are reflected in systems with limited configurability, poorly matched to the needs and practices of English hospitals. This situation echoes the history of comparable corporate information infrastructures - Enterprise Resource Planning systems - in the 1980s/1990s. UK government intervention prompted a similar swarming of immature, often unfinished, products into the market. This resulted, in both cases, in protracted and difficult implementation processes as vendors and adopters struggled to get the systems to work and match the circumstances of the adopting organisations. An analysis of the influence of the Installed Base on Information Infrastructures should explore how the evolution of COTS solutions is conditioned by the structure of adopter and vendor ‘communities’
In the absence of cancer registry data, is it sensible to assess incidence using hospital separation records?
BACKGROUND: Within the health literature, a major goal is to understand distribution of service utilisation by social location. Given equivalent access, differential incidence leads to an expectation of differential service utilisation. Cancer incidence is differentially distributed with respect to socioeconomic status. However, not all jurisdictions have incidence registries, and not all registries allow linkage with utilisation records. The British Columbia Linked Health Data resource allows such linkage. Consequently, we examine whether, in the absence of registry data, first hospitalisation can act as a proxy measure for incidence, and therefore as a measure of need for service. METHODS: Data are drawn from the British Columbia Linked Health Data resource, and represent 100% of Vancouver Island Health Authority cancer registry and hospital records, 1990–1999. Hospital separations (discharges) with principal diagnosis ICD-9 codes 140–208 are included, as are registry records with ICDO-2 codes C00-C97. Non-melanoma skin cancer (173/C44) is excluded. Lung, colorectal, female breast, and prostate cancers are examined separately. We compare registry and hospital annual counts and age-sex distributions, and whether the same individuals are represented in both datasets. Sensitivity, specificity and predictive values are calculated, as is the kappa statistic for agreement. The registry is designated the gold standard. RESULTS: For all cancers combined, first hospitalisation counts consistently overestimate registry incidence counts. From 1995–1999, there is no significant difference between registry and hospital counts for lung and colorectal cancer (p = 0.42 and p = 0.56, respectively). Age-sex distribution does not differ for colorectal cancer. Ten-year period sensitivity ranges from 73.0% for prostate cancer to 84.2% for colorectal cancer; ten-year positive predictive values range from 89.5% for female breast cancer to 79.35% for prostate cancer. Kappa values are consistently high. CONCLUSION: Claims and registry databases overlap with an appreciable proportion of the same individuals. First hospital separation may be considered a proxy for incidence with reference to colorectal cancer since 1995. However, to examine equity across cancer health services utilisation, it is optimal to have access to both hospital and registry files
I-SceI-Mediated Double-Strand Break Does Not Increase the Frequency of Homologous Recombination at the Dct Locus in Mouse Embryonic Stem Cells
Targeted induction of double-strand breaks (DSBs) at natural endogenous loci was shown to increase the rate of gene replacement by homologous recombination in mouse embryonic stem cells. The gene encoding dopachrome tautomerase (Dct) is specifically expressed in melanocytes and their precursors. To construct a genetic tool allowing the replacement of Dct gene by any gene of interest, we generated an embryonic stem cell line carrying the recognition site for the yeast I-SceI meganuclease embedded in the Dct genomic segment. The embryonic stem cell line was electroporated with an I-SceI expression plasmid, and a template for the DSB-repair process that carried sequence homologies to the Dct target. The I-SceI meganuclease was indeed able to introduce a DSB at the Dct locus in live embryonic stem cells. However, the level of gene targeting was not improved by the DSB induction, indicating a limited capacity of I-SceI to mediate homologous recombination at the Dct locus. These data suggest that homologous recombination by meganuclease-induced DSB may be locus dependent in mammalian cells
The changing association between socioeconomic circumstances and the incidence of colorectal cancer: a population-based study
Background:There is emerging evidence to suggest that the association between socioeconomic circumstances and colorectal cancer incidence has changed over recent decades.Methods:We conducted a descriptive population-based study to describe the relationship between socioeconomic circumstances and the incidence of colorectal cancer in a pre-screened population. Incident cases of colorectal cancer from the West of Scotland were identified from the Scottish Cancer Registry and European age-standardised incidence rates (EASR) were calculated. Socioeconomic circumstances were measured using the area-based Scottish Index of Multiple Deprivation (SIMD).Results:In total, 14?051 incident cases of colorectal cancer were recorded from 1999 to 2007. Incidence of colorectal cancer was associated with increased deprivation in men but not among women; an association that became evident from 2005 onwards. From 2005 to 2007, the deprivation gap in incidence among men was 13.3 per 100?000 (95% confidence interval 3.2-23.4), with rates 19.5% lower among the least deprived compared with the most deprived. This deprivation gap now accounts for an estimated 75 excess cases per year of male colorectal cancer in the West of Scotland.Conclusion:Deprivation was associated with higher incidence rates of male, but not female, colorectal cancer before the implementation of a national bowel screening programme
BRAF(E600)-associated senescence-like cell cycle arrest of human naevi
Most normal mammalian cells have a finite lifespan(1), thought to constitute a protective mechanism against unlimited proliferation(2-4). This phenomenon, called senescence, is driven by telomere attrition, which triggers the induction of tumour suppressors including p16(INK4a) (ref. 5). In cultured cells, senescence can be elicited prematurely by oncogenes(6); however, whether such oncogene-induced senescence represents a physiological process has long been debated. Human naevi ( moles) are benign tumours of melanocytes that frequently harbour oncogenic mutations ( predominantly V600E, where valine is substituted for glutamic acid) in BRAF(7), a protein kinase and downstream effector of Ras. Nonetheless, naevi typically remain in a growth-arrested state for decades and only rarely progress into malignancy (melanoma)(8-10). This raises the question of whether naevi undergo BRAF(V600E)- induced senescence. Here we show that sustained BRAF(V600E) expression in human melanocytes induces cell cycle arrest, which is accompanied by the induction of both p16(INK4a) and senescence- associated acidic beta-galactosidase (SA-beta-Gal) activity, a commonly used senescence marker. Validating these results in vivo, congenital naevi are invariably positive for SA-beta-Gal, demonstrating the presence of this classical senescence-associated marker in a largely growth-arrested, neoplastic human lesion. In growth-arrested melanocytes, both in vitro and in situ, we observed a marked mosaic induction of p16(INK4a), suggesting that factors other than p16(INK4a) contribute to protection against BRAF(V600E)- driven proliferation. Naevi do not appear to suffer from telomere attrition, arguing in favour of an active oncogene-driven senescence process, rather than a loss of replicative potential. Thus, both in vitro and in vivo, BRAF(V600E)-expressing melanocytes display classical hallmarks of senescence, suggesting that oncogene-induced senescence represents a genuine protective physiological process.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/62941/1/nature03890.pd
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